package cn.wolfcode.luowowo.interceptor;

import cn.wolfcode.luowowo.util.JsonResult;
import cn.wolfcode.luowowo.util.Md5Utils;
import com.alibaba.fastjson.JSON;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

/**
 * 签名拦截(防篡改)
 */
public class SignInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        if(!(handler instanceof HandlerMethod)){
            return  true;
        }

        //签名验证
        Map<String, String[]> map = request.getParameterMap();
        Set<String> keys = map.keySet();
        Map<String, Object> param = new HashMap<>();
        for (String s : map.keySet()) {
            System.out.println(s);
            if("sign".equalsIgnoreCase(s)){
                continue;
            }
            param.put(s, arrayToString(map.get(s)));
        }
        String signatures = Md5Utils.signatures(param);
        String sign = request.getParameter("sign");
        System.out.println(signatures);
        System.out.println(sign);
        if(sign == null || !sign.equalsIgnoreCase(signatures)){
            response.setContentType("text/json;charset=UTF-8");
            response.getWriter().write(JSON.toJSONString(new JsonResult(501,"签名校验失败","不好意思咯")));
            return false;
        }
        return true;
    }


    private String arrayToString(String [] array){

        StringBuilder sb = new StringBuilder(10);
        for (String s : array) {
            sb.append(s);
        }
        return sb.toString();
    }
}